usb: gadget: f_mass_storage: Disable eps during disconnect

When receiving a disconnect event from the UDC, the mass storage
function driver currently runs the handle_exception() routine
asynchronously.  For UDCs that support runtime PM, there is a
possibility the UDC is already suspended by the time the
do_set_interface() is executed.  This can lead to HW register access
while the UDC is already suspended.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/1635365407-31337-3-git-send-email-quic_wcheng@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>